The present invention relates to a light diverting device for diverting a part of the light energy transmitted through an optical conductor rod and for taking it out.
The present applicant has proposed various ways to focus solar rays or artificial rays by means of a lens or the like and guide them into an optical conductor, and further to transmit the rays through the optical conductor onto an optional desired place for use in illumination or for other purposes.
However, in such systems if the light energy propagating through the optical conductor can be diverted at the half way point and taken out from it, it is possible to greatly improve its effective use.
The present applicant has proposed, in view of the circumstances described above, a light diverting device capable of diverting a part of the light energy propagating through it and for also taking it out.
The light diverting device which the present applicant has proposed is comprised of a first optical conductor rod having a through-hole formed in a radial direction, a second optical conductor rod and a third optical conductor rod which are tightly inserted into the through-hole. The second optical conductor rod is firmly fixed by use of optical paste or the like. The edge surface portion of the second optical conductor rod in the through-hole is formed on a surface which is inclined in relation to the direction of the first optical conductor rod's axis. The third optical conductor rod has an inclined surface opposed to the inclined surface of the second optical conductor rod and is tightly inserted into the through-hole so as to be able to move back and forth in the through-hole. A groove is formed on the uppermost portion of the third optical conductor rod along the direction of its axis. Optical oil is poured into the gap between the inclined surface of the second optical conductor rod and the inclined surface of the third optical conductor rod through the groove. When the third optical conductor rod moves back and forth in the through-hole in relation to the second optical conductor rod, air in the gap between them is let out of it or air is sucked into it so as to facilitate the movement of the third optical conductor rod.
In such a manner, after pouring optical oil into the gap, when the third optical conductor rod is pushed forward the distance of the gap decreases and the level of optical oil rises. On the contrary, when the third optical conductor rod is pulled backward the distance of the gap increases and the level of optical oil falls.
The light rays propagating through the first optical conductor rod are reflected on the inclined surface of the second optical conductor rod in the area of the gap where there is no optical oil, while the light rays are passed through in the area of the gap where there is optical oil. Accordingly, the amount of light rays reflected by the inclined surface of the second optical conductor rod can be adjusted in accordance with the level of optical oil in the gap. Such adjustment can be performed by changing the insertion depth of the third optical conductor rod.
A fourth optical conductor rod is firmly fixed on the outer circumferential surface of the first optical conductor rod so as to cover tightly the inserted portion of the second optical conductor rod which is unitarily formed with the second optical conductor rod. In such a construction as mentioned heretofore, the light rays reflected by the inclined surface of the second optical conductor rod are taken out through the fourth optical conductor rod and transmitted through an optical conductor cable, which is connected with the fourth optical conductor rod, onto an optional desired place for use in illumination or for other purposes.
However, in the afore-mentioned light diverting device, optical oil in the space between the inclined surfaces comes in contact with the outside air through the groove formed in the third optical conductor rod. Consequently, there exists defects when the optical oil leaks through the groove or where dust or dirt enter into the optical oil, making difficult prolonged use of the oil. Furthermore, since the groove portion forms an air layer, light dispersion and a loss of light energy occur.